My partner and I have 5 kids. Girls are 17, 12, 5, boys 9, 8. We are both caucasion as our oldest two are. The youngest 3 are african-american. We had several discussions with our families about a multi-racial family, so they were prepared to accept all of our children, whatever their background was, for them to be a part of OUR family. One of my partners sisters has had a few issues with our kids being multi-racial, and she hasn't see us in about 4 years now. Her loss. Our kids come first in everything. I gained 35 pounds over the last 2 years by working over-nights, so I could be home in the evenings and weekends to be soccer coach for 4 teams and football on one.
Our relationship has suffered at times, since we don't get as much quality time alone as we used to. But we work thru things. You both need to be great communicators in your relationship to bring in a child. Talk about discipline techniques, who stays home/works odd shifts with the sick kid, etc. There are several adoption agencies in the US that we have used. I don't know much about foreign agencies. Start with google and good luck.